In recent years, data services have become popular for mobile communications systems, including the very popular so-called short messaging service (SMS), which makes use of underutilized bandwidth of signaling channels to allow short text messages. With SMS, users are able to exchange alphanumeric messages (up to 160 characters in length), and the messages are delivered within seconds of their being transmitted. Of course the networks traversed in providing the messages from one user to another must all be digital cellular networks. Although SMS was originally conceived as a paging mechanism for notifying users of the arrival of voicemail, it is now used primarily as a messaging service. A new use for SMS is a picture messaging application for cellular telephones that is presently being offered by the assignee hereof for allowing users to create and download picture messages into a proprietary mobile telephone (e.g. the Nokia 3210 GSM) and send the pictures to another, compatible proprietary telephone (e.g. another Nokia 3210 or a Nokia 8210 or Nokia 8850). With a likewise proprietary messaging platform (e.g. the Nokia Artus Messaging Platform), operators are able to enhance usage of SMS for their subscribers. Such a simple graphic message service provides a black-and-white picture, of a size for example of 72×28 pixels, along with a short greeting displayed below the picture; a maximum size of the greeting is for example 120 characters.
Co-owned and co-pending application Ser. No. 09/972,148 describes a picture editor, provided as software included in a mobile phone, that allows a user to create, store and edit pictures for use in messages sent via the mobile phone using for example SMS. The pictures can be created from scratch or can be created by modifying existing pictures. In addition, it is envisioned that pictures will be made available for downloading over the air interface by special picture downloading servers. Such pictures will usually be pictures created by companies interested in advertising a product or service the company offers for sale.
Since a company that provides a picture advertising a product or service will often want a user to be prevented from editing the picture (because for example the user might slightly alter the picture and use the picture for the user's own benefit, and the company might find the alteration disparaging to the product or service in some way).
What is therefore needed is a way to signal to a picture editor, such as one described in co-owned and co-pending patent application Ser. No. 09/972,148, whether a picture should or should not be protected from being altered by a user.